Lubricating oil compositions of improved rust inhibition

ABSTRACT

Lubricating oil compositions containing from about 0.01 to 5.0% of a tetra poly(oxyethylene)poly(oxypropylene) derivative of ethylenediamine having a molecular weight in the range of about 1650 to 15,000. These compositions are useful as engine oils, gear oils, hydraulic fluids and other industrial oils and exhibit improved rust inhibition properties as well as sludge elimination.

United States Patent 1 Papay et a].

[ Dec. 23, 1975 LUBRICATING OIL COMPOSITIONS OF IMPROVED RUST INHIBITION [75] Inventors: Andrew G. Papay, Manchester;

Brian W. Matthews, Crestwood, both of Mo.; Arthur S. Thomas, Wokingham, England [73] Assignee: Edwin Cooper, Inc., St. Louis, Mo.

[22] Filed: Aug. 24, 1973 [21] Appl. No.: 391,469

3,464,925 9/1969 Bendit et a1 252/51.5 R X 3,657,129 4/1972 Obermeiet 252/51.5 R 3,794,586 2/1974 Kimura et al. 252/5l.5 R 3,801,506 4/1974 Cross et al. 252/51.5 R X OTHER PUBLICATIONS Hackhs Chemical Dictionary, Grant, 4th Edition, 1969, p. 670, tetronic.

Primary Examiner-Delbert E. Gantz Assistant ExaminerAndrew H. Metz Attorney, Agent, or Firm-Bacon & Thomas [57] ABSTRACT Lubricating oil compositions containing from about 0.01 to 5.0% of a tetra poly(oxyethylene)poly(oxypropylene) derivative of ethylenediamine having a molecular weight in the range of about 1650 to 15,000. These compositions are useful as engine oils, gear oils, hydraulic fluids and other industrial oils and exhibit improved rust inhibition properties as well as sludge elimination.

5 Claims, No Drawings LUBRICATING OIL COMPOSITIONS F IMPROVED RUST IITION This invention relates to improved lubricating oil compositions which are particularly useful for both rust and emulsion sludge prevention.

The prior art, in US. Pat. No. 3,509,052, teaches that certain liquid polyoxyalkylene polyols of molecular weight in the range of about 1000 to 5000, known under the trade name Pluronic Polyols, are a preferred class of demulsifiers for use in engine oils for prevention of sludge formation. Certain polyoxyethylated amines, such as those marketed under the trade names Ethoduomeen and Ethomeen were mentioned in this patent but were not in the preferred class. 1

It has now been unexpectedly discovered that a different class of compounds, namely tetra poly(oxyethylene)-poly(oxypropylene) derivatives of ethylenediamine have superior properties as sludge and rust preventative in engine oil and other lubricating oil formulations. Certain of the ethylene diamine derivatives known under the trade name of Tetronics are especially useful for purposes of this invention.

The Tetronic series of tetra polyoxyalkyleneoxy derivatives of ethylenediamine are represented by the following general formula:

in which x and y, respectively, are integers which are so selected that the average molecular weight range of the poly(oxypropylene) hydrophobe unit is between about 500 and 7000 and the poly(oxyethylene) hydrophilic unit constitutes from about 10 to 80% by weight of the total molecule. The total molecular weight of these commercially available derivatives fall within the broad molecular weight range of 1650 to over 26,000.

For the purposes of the present invention, it is preferred to use liquid or pasty tetra poly(oxyethylene)- poly(oxypropy1ene) derivatives of ethylene diamine having the above formula, wherein x and y are so selected as to provide a total molecular weight within the range of from about 1650 to 15,000 and wherein the poly (oxyethylene) units constitute from about 10 to about 50 percent by weight of the molecule. Especially preferred are those amine derivatives of the class described which have a total molecular weight within the range of about 5,000 to 12,500 and a poly (oxyethylene) content of from about 10 to 40%. These are liquid or paste products which are readily soluble or dispersible in the lubricating oil base. These materials are well known in the art and may be produced by the process disclosed in US. Pat. No. 2,979,528.

The compositions of the invention comprise a major amount of a lubricating oil, natural or synthetic, containing from about 0.01 to 5% by weight of a tetra poly(oxyethylene)-poly(oxypropylene) derivative of the formula given above, wherein x and y are so selected as to provide a total average molecular weight within the range of about 1650 to 15,000 and wherein the poly(oxyethylene) units constitute from about to about 50% by weight of the molecule.

It will be understood that the lubricating oil compositions of this invention may optionally contain additional conventional additives such as antioxidants; dispersants, especially ashless dispersants of the succinimide type; metal based detergents; corrosion inhibitors; extreme pressure agents, viscosity index improvers; pour point depressants and other conventional additives as desired. These are all well known in the art and are described in US. Pat. No. 3,509,052 and other published literature and will not be described in detail herein. Such conventional additives are used in the amounts necessary to perform their known functions and may comprise from about 1 to 20% of the lubricating oil formulation with the remainder constituting the lubricating oil base and tetra poly(oxyethylene)- poly(oxypropylene) derivative of ethylene diamine.

Further, it will be understoodo that hydraulic oil and gear oil formulations, as well as engine oil formulations, containing a lubricating oil base and tetra poly(oxyethylene) poly (oxypropylene) derivative of ethylene diamine are within the scope of this invention. For example, the amine derivative may be incorporated with an SA-lOW to SA-4O weight lubricating oil to provide a suitable hydraulic oil having improved antisludging and anti-rust properties.

The lubricating oil base may be an animal or vegetable oil, mineral oil or synthetic oil, or mixture thereof. For example, castor oil is commonly used as a base component in hydraulic oils as well as in lubricating oils, and fatty oils such as lard oil, neatsfoot oil and sperm oil are used for special purpose lubricants and greases. In most instances the composition of the invention will comprise a mineral lubricating oil or synthetic lubricating oil base and will be used as a hydraulic or engine oil. Such lubricating base oils are well known in the art and are described in detail, for example, in the aforementioned US. Pat. No. 3,509,052 and in other published literature.

Where ashless dispersants are used they may be of the ester or succinimide type which includes the esters, acidic esters, half-esters-half-amides, acidic amides, amidines, amine salts and metal salts of substituted succinic acids wherein the the substituent contains at least about fifty aliphatic carbon atoms. These substances are well known in the art. For example, reaction products of high molecular weight polyalkylene substituted succinic acids and anhydrides with ethylene polyamines such as described in US. Pat. No. 3,172,892 may be used. They may be used in the engine oil compositions in the desired dispersant amounts, e.g., up to about 10% by weight based on the total weight of the composition.

Metal containing detergents include the well known over-based alkaline earth metal salts such as the calcium, barium and magnesium salts of alkyl benzene sulphonic acids and of phosphosulphurized hydrocarbons, for example polyisobutylenes, and such basic additives as alkaline earth metal or magnesium alkyl phenates or their corresponding sulphurized derivatives. These additives may be used in the desired detergent amounts, e.g., about 0.5% to 7.5% by weight based on the total weight of the composition.

Any of the known extreme pressure agents, corrosion-inhibiting and oxidation inhibiting agents may be used in the composition of the invention in amounts which usually comprise no more than about 0.1 to 5% by weight of the total weight of the composition. Typical corrosion inhibitors are compounds of the Group II metals with sulphur and phosphorus, e.g., the barium and zinc phosphorodithionates. However, the invention is in no way limited to the use of these specific materials.

The following are examples of this invention, but do not limit the invention in any way.

EXAMPLE 1 An SAE 30 M1L-L-2104C type oil containing a conventional calcium, barium and zinc detergent inhibitor EXAMPLE 7 An oil as in Example 6, but with 0.05% wt. of Tetronic 1501 added.

The above formulations as described in Examples 1 to 7 were evaluated for rust protection in the Oldsmobile IIC test using the General Motors 11C test procedure.

system with succinimide type ashless dispersant was formulated. The base stock was a Middle East Solvent refined 95V] stock, and the blended oil had the following analysis:

Zn (wt. 0.08

Ca (wt. 0.25

Ba (wt. 0.13 This oil is designated formulation A.

EXAMPLE 2 An oil as in Example 1, but with 0.05% wt. of Tetronic 1101 added. Tetronic 1101 is a tetra poly(oxyethylene)-poly(oxypropylene) derivative of ethylene diamine of the given formula which has a total molecular weight of 5600 and a poly(oxyethylene) content of about by weight based on the total weight of the molecule.

EXAMPLE 3 An oil as in Example 1, but with 0.1% wt. of Tetronic 1 101 added.

EXAMPLE 4 An oil as in Example 1, but with 0.05% wt of Tetronic 1501 added. Tetronic 1501 is a derivative of the given formula which has an average molecular weight of 7900 and a poly(oxyethylene) content of about 10%.

EXAMPLE 5 An oil as in Example 1, but with 0.1% wt. of Tetronic 1304 added. Tetronic 1304 is a derivative of the given formula which has an average molecular weight of 10,500 and a poly(oxyethylene) content of about 40%.

EXAMPLE 6 Another area of performance in which the alkoxylated amines of the present invention offer benefits is in the control of rocker cover emulsion sludge. This emulsion sludge is usually an oil in water emulsion and it is formed by the mechanical agitation of oil and water produced by condensation of blowby gases in the rocker box area. This emulsion sludge can be formed under various conditions, but it is usually accentuated by low ambient temperatures and stop-start driving conditions.

An engine test has been developed for evaluating the emulsion sludge forming tendencies of crankcase oils. This procedure is based on a 4 cylinder Ford 1500 cc engine. The engine is built to IP246/69T cover. The crankcase breather outlet is blanked off to increase the flow of blowby gases to the rocker cover area. At the end of test, the rocker cover is rated for emulsion sludge, and the amount of sludge formed is weighed.

The formulated oils described in Examples 6 and 7 above and the formulations of Examples 8-15 below were evaluated for emulsion sludge performance. The results of this evaluation are set forth in Table 2 below.

EXAMPLE 8 An SAE l0W/30 MIL-L-46l52 type oil containing a conventional calcium and zinc detergent inhibitor system, a succinimide type ashless dispersant and a conventional non-dispersant methacrylate V1 improver was formulated using a solvent refined Middle East Vl base stock. The blended oil had the following analysis:

Ca (wt. 0.15

Zn (wt. 0.1 This oil is designated formulation C.

EXAMPLE 9 An oil as in Example 8, but with 0.025% wt. Tetronic 1 101 added.

EXAMPLE 10 An oil as in Example 8, but with 0.025% wt. Tetronic l 101 added.

EXAMPLE 1 1 An oil as in Example 8, but with 0.05% wt. Tetronic 1301 added. Tetronic 1301 is an amine derivative of the given formula which has a total molecular weight of 6800 and a poly(oxyethylene) content of about 10%.

ous polyalkoxylated amines (Tetronics) is shown below.

TABLE 3 ASTM D-l40l Additive Conc. Oil, ml. Water, ml. Emulsion Time, min.

None 40 14 26 30 None 37 9 34 30 Tetronic 904 0.05 40 40 Tetronic 904 0.02 40 40 0 5 Tetronic 904 0.01 40 39 1 Tetronic 904 0.01 40 40 0 l5 Tetronic 1101 0.05 40 39 l 5 Tetronic 1101 0.05 40 40 0 l0 Tetronic 1104 0.05 40 37 3 5 Tetronic 1104 0.05 40 38 2 30 Tetronic 1301 0.05 40 40 2 5 Tetronic 1301 0.02 40 38 2 5 Tetronic 1301 0.02 40 40 0 25 Tetronic 1301 0.01 40 39 l 5 Tetronic 1301 0.01 40 40 0 Tetronic 1302 0.05 40 38 2 5 Tetronic 1302 0.05 40 40 0 Tetronic 1304 0.05 40 39 l 5 Tetronic 1304 0.05 40 40 O 20 Tetronic 1501 0.05 40 39 1 5 Tetronic 1501 0.05 40 40 0 10 Tetronic 1502 0.05 40 39 l 5 Tetronic 1502 0.05 40 40 O 20 Tetronic 1504 0.05 40 39 l 5 Tetronic 1504 0.05 40 40 0 10 EXAMPLE 12 An oil as in Example 8, but with 0.0125% wt. Tetronic 1501 added.

EXAMPLE 13 An oil as in Example 8, but with 0.25% wt. Tetronic 1501 added.

EXAMPLE 14 An oil as in Example 8, but with 0.037% wt. Tetronic 1501 added.

EXAMPLE 15 An oil as in Example 8, but with 0.05% wt. Tetronic 1501 added.

The above oils, as described in Examples 6 to 15, were evaluated in the Ford 1500 cc engine emulsion sludge test.

TABLE 2 EMULSlON SLUDGE TEST RESULTS AT PERFORMANCE LEVEL MlL-L-46l52 Tetronic 904 is an amine derivative of the given formula which has a molecular weight of 7500 and a poly- (oxyethylene) content of about 40%. Tetronic 1104 is an amine derivative of the given formula which has a molecular weight of 8300 and a poly(oxyethylene) content of about 40%. Tetronic 1302 is an amine derivative of the given formula having a molecular weight of 7800 and a poly(oxyethylene) content of about 20%. Tetronic 1504 is an amine derivative of the given formula having a molecular weight of 12,500 and a poly- (oxyethylene) content of about 40%.

EXAMPLE 17 An SAE l0W/30 MlL-L-46l52 type oil containing a non-dispersant VI improver and a conventional calcium, zinc and magnesium detergent inhibitor system and a conventional calcium, zinc and magnesium detergent inhibitor system with succinimide type ashless dispersant was evaluated with various demulsibility A hydraulic oil containing 0.06% Zn, 0.06% P, 0.10% S, and 0.07% Ca was tested for demulsibility according to ASTM Method D-140l whereby the time of separation of a warm, previously stirred emulsion of 40 ml. of water and 40 ml. of oil is measured. The effect of variagents by the ASTM D-1401 method.

In addition to using water in this test, a further series of tests were carried out replacing the water with 0.2% aqueous formic acid. It was felt that this would simulate the acidic conditions generated in an engine after considerable blowby condensation had taken place.

An analysis of the formulated oil used in this test is as follows:

CA (wt. 0.06

Zn (wt. 0.13

Mg (wt. 0.09

The results of the ASTM D1401 tests are contained in Table 4 and they show the advantages to be gained from the use of Tetronic demulsifiers.

TABLE 4 VOLUME (ml) OF AQUEOUS PHASE SEPARATED FROM ASTM D- 1401 Aqueous Time, Additive Phase min. None A B C D E F Water 5 32 32 37 35 25 18 33 32 37 35 31 27 34 33 32 37 35 32 30 20 34 33 32 37 35 33 32 34 33 33 37 36 33 34 34 33 33 37 36 34 34 Aqueous 10 0 0 27 29 34 31 0 Formic l5 0 0 27 29 31 0 Acid 20 0 0 28 29 35 31 0 25 1 l 28 29 35 32 3 30 3 l 29 29 35 32 4 The following additives were used at 0.1% weight in the above tests:

Additive A pentaethoxylated dodecylphenol B Tetronic 1501 C Tetronic 1301 D Tetronic 1101 E Tetronic 904 F Sorbitan Trioleate EXAMPLE 18 A sulfur-phosphorus MIL-L-2105B type gear oil in SAE 90 grade oil was tested together with various demulsifiers added at 0.05% concentration in the oil according to ASTM Method D-2711 using the modification for EP lubricants. The results are given in Table 5 below.

(1)p|us 3 ml. emulsion (Zlplus 30 ml. emulsion Additive A Tetronic 1501 B Tetronic 1 101 C Tetronic 1302 D Tetronic 701 Tetronic 701 is an amine derivative of the given formula having a molecular weight of 3600 and a poly (oxyethylene) content of 10%.

EXAMPLE 19 In addition to evaluating the Tetronic products in gear lubricants using the ASTM D-2711 method, two ethoxylated amines were evaluated. The results show that the ethoxylated amines produce considerable emulsion and are inferior to the Tetronic products.

A MIL-L-46152 type oil containing a conventional nondispersant VI irnprover and succinimide type ashless dispersant together with a calcium, magnesium and zinc detergent-inhibitor system containing Ca 0.06%, Zn 0.13% and Mg 0.09% was formulated. This oil, with and without addition of 0.1% of Tetronic 1101, was tested in the acid neutralization (H Br) test of MIL-L- 21260B.

Additive H Br Test Result Tetronic 1101 Pass None Fail We claim:

1. In a lubricating composition comprising a major amount of an oil of lubricating viscosity and conventional additives selected from the group consisting of internal combustion engine oil additives, gear oil additives and hydraulic oil additives in an amount sufficient to effect each additives attendant function, the improvement comprising as a further additive from 0.01 to 5.0 percent of a tetra poly (oxyethylene) poly (oxypropylene) derivative of ethylenediamine having the formula,

wherein x and y are so selected that said derivative has a molecular weight in the range of from about 1650 to 15,000 and a poly( oxyethylene) content of about 10 to 2. The lubricating oil composition of claim 1 wherein x and y are so selected that the derivative has a molecular weight in the range of from about 5,000 to 12,500 and poly (oxyethylene) content of about 10 to 40%.

3. The lubricating composition of claim 1 wherein internal combustion engine oil additives are present and in which'said additives comprise an ashless dispersant selected from the group consisting of the metal salts, amine salts, amides, imides, amidines, and esters of substituted succinic acids having a substitutent containing at least about 50 aliphatic carbon atoms.

4. The lubricating oil composition of claim 1 wherein gear oil additives are present.

5. The lubricating oil composition of claim 1 wherein hydraulic oil additives are present.

IN THE CLAIMS:

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,928,219

DATED December 23, 1975 |NvENTOR(5) Andrew G. Papay, Brian W Matthews, Arthur S. Thomas It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

IN THE SPECIFICATION:

Column 1, lines 31-33, correct the structural formula to read:

--- H(C H 0) (C3H o) (c H o) (c H 0) H 2 4 Y 6 3 6 x 2 4 y CH CH Claim 1, column 8, lines 43-45, correct the structural formula to read:

Signed and Sealed this thirteenth Day of I-1,1976 [SEAL] Arrest.

RUTH C. MASON Arresting Officer IN THE CLAIMS:

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIUN PATENT NO. 3, 928,219

DATED December 23, 1975 |NVENTOR(5) Andrew G. Papay, Brian W. Matthews, Arthur S. Thomas It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below;

IN THE SPECIFICATION:

Column 1, lines 31-33, correct the structural formula to read:

CH CH N Claim 1, column 8, lines 43-45, correct the structural formula to read:

H(CHO)(CHO) (CHO)(CHO)H 24y3 6x 36X24Y Signed and Sealed this thirteenth Day of April1976 [SEAL] Arrest.

RUTH c. MASON c. MARSHALL DANN Allcsling Offl'tr ('ummissr'unvr HflflIU/IIS and Trademarks 

1. IN A LUBRICATING COMPOSITION COMPRISING A MAJOR AMOUNT OF AN OIL OF LUBRICATING VISCOSITY AND CONVENTIONAL ADDITIVES SELECTED FROM THE GROUP CONSISTING OF INTERNAL COMBUSTION ENGINE OIL ADDITIVES, GEAR OIL ADDITIVES AND HYDRAULIC OIL ADDITIVES IN AN AMOUNT SUFFICIENT TO EFFECT EACH ADDITIVES ATTENDANT FUNCTION, THE IMPROVEMENT COMPRISING AS A FURTHER ADDITIVE FROM 0.01 TO 5.0 PERCENT OF A TETRA POLY (OXYETHYLENE) - POLY (OXYPROPYLENE) DERIVATIVE OF ETHYLENEDIAMINE HAVING THE FORMULA,
 2. The lubricating oil composition of claim 1 wherein x and y are so selected that the derivative has a molecular weight in the range of from about 5,000 to 12,500 and poly (oxyethylene) content of about 10 to 40%.
 3. The lubricating composition of claim 1 wherein internal combustion engine oil additives are present and in which said additives comprise an ashless dispersant selected from the group consisting of the metal salts, amine salts, amides, imides, amidines, and esters of substituted succinic acids having a substitutent containing at least about 50 aliphatic carbon atoms.
 4. The lubricating oil composition of claim 1 wHerein gear oil additives are present.
 5. The lubricating oil composition of claim 1 wherein hydraulic oil additives are present. 